The ucceful Treatment of Gatifloxacin-reitant taphylococcu aureu Keratiti With Zymar® (Gatifloxacin 0.3%) in a NZW Rabbit Model

Purpoe To determine whether gatifloxacin-reitant . aureu (Gat-R-a) keratiti could be uccefully treated with topical Zymar® (gatifloxacin 0.3%) in a rabbit model. Deign Experimental animal tudy. Method Two eparate tudie were performed each uing two clinical iolate of Gat-R-a, with MIC of 12 and 64 μg/ml to gatifloxacin. tudy 1 conited of four treatment group (Zymar®, Quixin® [levofloxacin 0.5%], Ciloxan® [ciprofloxacin 0.3%], and aline).tudy 2 conited of Zymar®, cefazolin 50 mg/ml, vancomycin 50 mg/ml, and aline. Rabbit were infected intratromally with 2,000 cfu in both eye. Topical therapy began after four hour, every 15 minute for 5 hour. After therapy, the eye were graded for clinical ign of infection (blephariti, conjunctiviti, iriti, corneal edema, and corneal infiltrate), and the cornea were homogenized to determine viable bacterial count. Reult tudy 1: for both iolate, Zymar®-treated eye demontrated ignificantly lower clinical core compared with Ciloxan® and aline, and ignificantly decreaed the number of viable bacteria recovered compared with all group. tudy 2: for both iolate, Zymar® and cefazolin demontrated ignificantly lower clinical core compared with vancomycin and aline. Zymar®, cefazolin, and vancomycin ignificantly decreaed the number of viable bacteria recovered compared with the aline control. Concluion We demontrated the “Proof of Principle” that in vitro antibiotic reitance, baed on CLI tandard, doe not alway correlate with in vivo treatment failure in the eye. An aggreive treatment regimen with Zymar® appear to overcome in vitro reitance, reulting in the ucceful treatment of Gat-R-a infection in the NZW rabbit keratiti model.